My name is Gabrielle, I am a Master's student at UNIFESP (Federal University of São Paulo), SP, Brazil.

I'm using UCSF Chimera to analyze the secondary structure of some peptides that I'm studying.

When I load the .pdb file in the program, it generates a different structure than the one desired. In the examples below, we have two structures alpha helix and random coil, but the images generated are different and I don't understand why.

Could you help me, explaining what is happening, or what I should do to have the image as in the first figure (NATTP_05 chimera).

Thanks